Deprecation warnings for grammar regular expressions

[geographika]

See examples in https://api.travis-ci.org/v3/job/433072834/log.txt

/home/travis/build/geographika/mappyfile/.tox/py36/lib/python3.6/site-packages/lark/lexer.py:159: DeprecationWarning: Flags not at the start of the expression '(?P<CCOMMENT>\\/(?s)[' (truncated)

These fill up the logs causing:

The job exceeded the maximum log length, and has been terminated.

The flags in the grammar file need to be moved to the front of the string to correct this.

[geographika]

Fixed in 0.7.6